1. Field of the Invention
This invention relates to a novel resin composite consisting of a thermosetting resin and a thermoplastic resin or a photosensitive resin and a thermoplastic resin, and more particularly to a resin composite consisting of an epoxy resin and polyethersulphone (hereinafter abbreviated as PES) or a so-called PES modified epoxy resin, or a resin composite of an acrylic resin and polyether sulphone or a so-called PES modified acrylic resin as well as a method of producing the same.
2. Description of the Related Art
As the technique for the resin composite, there is a typical technique of improving the properties of a thermosetting resin by mixing the thermosetting resin with a thermoplastic resin. For example, in the mixed system (PES modified epoxy resin) of epoxy resin and polyethersulphone (PES), the toughness of the epoxy resin is improved by a co-continuous two-phase structure formed between the epoxy resin and PES (Keizo Yamanka and Takashi Inoue, Polymer, Vol. 30, p 662 (1989)).
In the above PES modified epoxy resin formed by mixing two resins, the toughness is improved as compared with that of the epoxy resin alone because the PES modified epoxy resin has a resin structure as mentioned below. That is, in the mixed system of PES and epoxy resin such as bisphenol A-type epoxy resin, when it is cured at a high temperature, a state of completely dissolving the epoxy resin and PES (compatible state) is not formed but a state of separately mixing the thermosetting resin and the thermoplastic resin through spinodal decomposition (phase separating state) is formed. The latter case is apparently a state of connecting spherical epoxy domains to each other and regularly dispersing them into the matrix of PES, which is a so-called co-continuous two-phase structure between the epoxy resin and PES.
The co-continuous two-phase structure is formed by the phase separating state between the epoxy resin and PES, and is a structure of merely dispersing the spherical epoxy domains produced by spinodal decomposition into the PES matrix. Therefore, the effect of dispersing PES into the epoxy resin is developed, but the properties of PES itself can not be enhanced. Because, when a glass transition temperature of the composite having the co-continuous two-phase structure is measured by the measurement of dynamic viscoelasticity, two values of glass transition temperature peak are observed and hence it is considered that the interaction of the epoxy resin and PES as a matrix is weak.
The above knowledge on the co-continuous two-phase structure is true in case of a mixed system of a photosensitive resin and a thermoplastic resin, e.g. a mixed system of acrylic resin and polyethersulphone (PES modified acrylic resin).